The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Theresa M. Lee - One of the best experts on this subject based on the ideXlab platform.
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Octodon Degus (Molina 1782): A Model in Comparative Biology and Biomedicine
Cold Spring Harbor protocols, 2013Co-Authors: Alvaro O. Ardiles, Francisco Bozinovic, Luis A Ebensperger, Theresa M. Lee, John Ewer, Monica L. Acosta, Alfredo Kirkwood, Agustín D. Martínez, Adrian G. PalaciosAbstract:One major goal of integrative and comparative biology is to understand and explain the interaction between the performance and behavior of animals in their natural environment. The Caviomorph, Octodon Degus, is a native rodent species from Chile, and represents a unique model to study physiological and behavioral traits, including cognitive and sensory abilities. Degus live in colonies and have a well-structured social organization, with a mostly diurnal–crepuscular circadian activity pattern. More notable is the fact that in captivity, they reproduce and live for between 5 and 7 years and exhibit hallmarks of neurodegenerative diseases (including Alzheimer's disease), diabetes, and cancer.
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Characterization of the Estrous Cycle in Octodon Degus
Biology of reproduction, 2010Co-Authors: Megan M Mahoney, Megan H. Hagenauer, Brooke V. Rossi, Theresa M. LeeAbstract:We characterized the reproductive cycle of Octodon Degus to determine whether reproductive maturation is spontaneous in juveniles and if ovarian cyclicity and luteal function are spontaneous in adults. Laboratory-reared prepubertal and adult females were monitored for vaginal patency and increased wheel-running. Sexual receptivity was assessed by pairing adult females with a male 1) continuously, 2) at the time of vaginal patency, or 3) following estradiol treatment. Blood samples were assayed for estradiol and progesterone concentrations on Days 1, 4, 8, and 16 relative to vaginal opening. Ovarian tissues were collected 6 and 16 days after behavioral estrus and 6 days after copulation for histology. In juveniles, the onset of cyclic vaginal patency and increased wheel-running activity was spontaneous, occurred in the absence of proximal male cues, and appeared at regular intervals (17.5 ± 1.4 days). In adults, vaginal patency and increased wheel-running occurred cyclically (21.2 ± 0.6 days) in the absence of proximal male cues, and these traits predicted the time of sexual receptivity. Corpora lutea develop spontaneously and are maintained for 12-14 days. The ovaries had well-developed corpora lutea 6 days after mating and 6 days after estrus without mating. Progesterone concentrations were highest in the second half of the cycle when corpora lutea were present and estradiol concentrations peaked on the day of estrus. Thus, female Degus appear to exhibit a spontaneous reproductive cycle consistent with other Hystricognathi rodents. Octodon Degus is a novel model with which to examine the mechanisms underlying different reproductive cycles.
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Odor-facilitated reentrainment in male and female juvenile Octodon Degus
Physiology & behavior, 2006Co-Authors: Tammy J Jechura, Cheryl D. Stimpson, Theresa M. LeeAbstract:The social, diurnal rodent, Octodon Degus, exhibits faster reentrainment rates of circadian activity when exposed to olfactory social cues from females already entrained to the new light cycle (donors) during reentrainment after a phase shift of the light:dark (LD) cycle. However, adult Degus display sex differences in the use of olfactory stimuli to accelerate reentrainment, with intact males requiring odors from at least two females for accelerated reentrainment, while odors from a single female are sufficient for faster recovery for females. In addition, adult gonadal hormones modulate responsiveness to the rate-enhancing olfactory stimuli. The present study examines responsiveness to reentrainment-accelerating odors in juvenile animals just prior to puberty. We report that the sex difference in sensitivity observed in adults is not evident in juveniles; both males and females, when exposed to odors from one unfamiliar adult, accelerated reentrainment of circadian activity after a 6-h phase-advance of the LD cycle. In conjunction with adult data, these results suggest that the sensitivity-reducing role of testosterone does not change across the life span, while the sensitivity-enhancing role of ovarian hormones in females occurs only post-pubertally.
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Odor-specific effects on reentrainment following phase advances in the diurnal rodent, Octodon Degus
American journal of physiology. Regulatory integrative and comparative physiology, 2006Co-Authors: Tammy J Jechura, Megan M Mahoney, Cheryl D. Stimpson, Theresa M. LeeAbstract:Reentrainment following phase shifts of the light-dark (LD) cycle is accelerated in Octodon Degus in the presence of olfactory social cues (i.e., odors) produced by conspecifics. However, not all o...
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Ovarian hormones influence olfactory cue effects on reentrainment in the diurnal rodent, Octodon Degus
Hormones and behavior, 2004Co-Authors: Tammy J Jechura, Theresa M. LeeAbstract:Octodon Degus, a social hystricomorph rodent, responds to olfactory cues from a gonadally intact female entrained to a light-dark cycle (LD) by accelerating reentrainment of running wheel activity following a 6-h phase advance of the LD cycle. In this study, we examined the role of ovarian hormones in the production of and responsiveness to olfactory social cues in females. Experiment 1: intact females were sequentially phase-advanced 6 h with photic cues alone, or in the presence of an intact female donor, ovariectomized (OVX) donor, a castrated male, or a castrated male with testosterone replacement. Acceleration of reentrainment occurred only in the presence of the intact female donor while reentrainment was delayed by OVX donors. Experiment 2: OVX females undergoing a 6-h phase advance did not accelerate reentrainment in the presence of an intact female donor compared to reentrainment with photic cues alone. Thus, ovarian hormones are necessary for both the production of and responsiveness to olfactory cues. Experiment 3: OVX females implanted with estrogen-filled Silastic capsules did not accelerate reentrainment following the 6-h phase advance in the presence of an intact donor, whereas animals implanted with a combination of estrogen- and progesterone-filled capsules (Experiment 4) reduced the length of time needed to reentrain in the presence of an intact donor. Therefore, combined progesterone and estrogen are sufficient for responsiveness to the effective olfactory cue in intact donor females. These data clarify that the sex difference in sensitivity to non-photic odor effects on circadian reentrainment is caused by both the testosterone's inhibitory effects (Octodon Degus. J. Biol. Rhythms 18 (2003) 43-50) and the enhancing effects of progesterone and estrogen.
Francisco Bozinovic - One of the best experts on this subject based on the ideXlab platform.
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Andrographolide Reduces Neuroinflammation and Oxidative Stress in Aged Octodon Degus
Molecular Neurobiology, 2020Co-Authors: Carolina B. Lindsay, Francisco Bozinovic, Juan M. Zolezzi, Daniela S. Rivera, Pedro Cisternas, Nibaldo C. InestrosaAbstract:Alzheimer’s disease (AD) is a devastating neurodegenerative disorder in which superior brain functions, such as memory and cognition, are impaired. Currently, no effective treatment is available for AD. Although andrographolide (ANDRO), a compound extracted from the herb Andrographis paniculata , has shown interesting effects in models of several diseases, including AD, its effects on other molecular changes observed in AD, such as neuroinflammation and oxidative stress, have not yet been studied. To evaluate the impact of ANDRO-based intervention on the levels of amyloid-β (Aβ) and neuroinflammatory and oxidative stress markers in the brains of aged Octodon Degus , a Chilean rodent, fifty-six-month-old O. Degus were treated intraperitoneally with 2 or 4 mg/kg ANDRO. Vehicle-injected and 12-month-old O. Degus were used as positive controls. Then, the protein levels of selected markers were assessed via immunohistochemistry and immunoblotting. ANDRO significantly reduced the total Aβ burden as well as astrogliosis and interleukin-6 levels. Moreover, ANDRO significantly reduced the levels of 4-hydroxynonenal and N-tyrosine adducts, suggesting a relevant reduction in oxidative stress within aged O. Degus brain. Considering that O. Degus has been proposed as a potential “natural” model for sporadic AD due to the development of neuropathological markers that resemble this pathology, our results suggest that ANDRO should be further studied to establish its potential as a therapeutic drug for AD.
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Octodon Degus (Molina 1782): A Model in Comparative Biology and Biomedicine
Cold Spring Harbor protocols, 2013Co-Authors: Alvaro O. Ardiles, Francisco Bozinovic, Luis A Ebensperger, Theresa M. Lee, John Ewer, Monica L. Acosta, Alfredo Kirkwood, Agustín D. Martínez, Adrian G. PalaciosAbstract:One major goal of integrative and comparative biology is to understand and explain the interaction between the performance and behavior of animals in their natural environment. The Caviomorph, Octodon Degus, is a native rodent species from Chile, and represents a unique model to study physiological and behavioral traits, including cognitive and sensory abilities. Degus live in colonies and have a well-structured social organization, with a mostly diurnal–crepuscular circadian activity pattern. More notable is the fact that in captivity, they reproduce and live for between 5 and 7 years and exhibit hallmarks of neurodegenerative diseases (including Alzheimer's disease), diabetes, and cancer.
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Do changes in dietary chemistry during ontogeny affect digestive performance in adults of the herbivorous rodent Octodon Degus
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2007Co-Authors: Pablo Sabat, Francisco BozinovicAbstract:We characterize the flexibility in digestive performance in Degus (Octodon Degus) an herbivorous rodent. We tested the hypothesis that dietary and physiological-digestive flexibility are correlated. Degus were fed with artificial diets of different chemical composition from weaning to adulthood and their digestive performance was measured through records of apparent digestibility. The starch content of the acclimation diet was not correlated with protein digestibility nor was it correlated with starch digestibility. In addition, digestive tract morphology was not affected by dietary treatments. Hence, an absence of morphological and physiological flexibility related to digestive traits was observed in Degus. The lower flexibility in digestive performance given by our dietary experimental treatments of Degus, may be an evolutionary constraint related to their specialized herbivorous food habits.
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Interplay between acclimation time and diet quality on basal metabolic rate in females of Degus Octodon Degus (Rodentia: Octodontidae).
Journal of Zoology, 2000Co-Authors: Claudio Veloso, Francisco BozinovicAbstract:The effect of diet quality on basal metabolic rate (BMR) over time was studied in female Octodon Degus. Degus fed on a low-quality diet maintained a constant BMR over time, while those fed on a high-quality diet showed an increased BMR after 30 days. After 120 days of dietary acclimation, individuals fed on a high-quality diet exhibited comparatively higher BMRs. Thus, we hypothesize that when environmental food quality is high, Degus are able to increase their BMR quickly, allowing high rates of biosynthesis.
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Communal burrowing in the hystricognath rodent, Octodon Degus: a benefit of sociality?
Behavioral Ecology and Sociobiology, 2000Co-Authors: Luis A Ebensperger, Francisco BozinovicAbstract:We examined the hypothesis that a main benefit of group-living in the semifossorial rodent, Octodon Degus (Rodentia: Octodontidae), is to decrease individual cost of burrow construction. We contrasted the digging behavior of groups of three same-sex, adult-sized individuals with that of solitary Degus. The behavior of singles and trios was recorded inside a large terrarium partially filled with natural soil and under controlled conditions of food, light, and temperature. The observation that Degus in groups do not decrease their burrowing time or frequency of digging compared with solitary diggers does not support the hypothesis that communal burrowing is a primary cause of degu sociality. On the other hand, the observation that Degus in groups removed significantly more soil per capita than solitary digging Degus, and that grouped individuals coordinated their digging – group members burrowed mostly in the same sites and formed digging chains –, suggests that social burrowing may potentially reduce the cost of burrow construction in the long term. We suggest that such long-term benefits will be a consequence rather than a cause of degu group-living.
Benjamin Dehay - One of the best experts on this subject based on the ideXlab platform.
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Lack of spontaneous age-related brain pathology in Octodon Degus: a reappraisal of the model.
Scientific reports, 2017Co-Authors: Mathieu Bourdenx, Sandra Dovero, Marie-laure Thiolat, Erwan Bezard, Benjamin DehayAbstract:Lack of spontaneous age-related brain pathology in Octodon Degus : a reappraisal of the model
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Lack of spontaneous age-related brain pathology in Octodon Degus: a reappraisal of the model.
Scientific Reports, 2017Co-Authors: Mathieu Bourdenx, Sandra Dovero, Marie-laure Thiolat, Erwan Bezard, Benjamin DehayAbstract:Neurodegenerative diseases are characterized by the degeneration of specific brain areas associated with accumulation of disease-related protein in extra- or intra-cellular deposits. Their preclinical investigations are mostly based on genetically-engineered animals. Despite their interest, these models are often based on high level of disease-related protein expression, thus questioning their relevance to human pathology and calling for the alternate use of ecological models. In the past few years, Octodon Degus has emerged as a promising animal model displaying age-dependent Alzheimer's disease-related pathology. As neurodegenerative-related proteins often co-deposit in the brain of patients, we assessed the occurrence of α-synuclein-related pathology in this model using state-of-the-art immunohistochemistry and biochemistry. Despite our efforts and in contrast with previously published results, our study argues against the use of Octodon Degus as a suitable natural model of neurodegenerative disorder as we failed to identify either Parkinson's disease- or Alzheimer's disease-related brain pathologies.
Juan Antonio Madrid - One of the best experts on this subject based on the ideXlab platform.
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Period Gene Expression in the Brain of a Dual-Phasing Rodent, the Octodon Degus
Journal of Biological Rhythms, 2013Co-Authors: Beatriz Baño Otalora, Megan H. Hagenauer, Juan Antonio MadridAbstract:Clock gene expression is not only confined to the master circadian clock in the suprachiasmatic nucleus (SCN) but is also found in many other brain regions. The phase relationship between SCN and extra-SCN oscillators may contribute to known differences in chronotypes. The Octodon Degus is a diurnal rodent that can shift its activity-phase preference from diurnal to nocturnal when running wheels become available. To understand better the relationship between brain clock gene activity and chronotype, we studied the day-night expression of the Period genes, Per1 and Per2, in the SCN and extra-SCN brain areas in diurnal and nocturnal Degus. Since negative masking to light and entrainment to the dark phase are involved in the nocturnalism of this species, we also compare, for the first time, Per expression between entrained (EN) and masked nocturnal (MN) Degus. The brains of diurnal, MN, and EN Degus housed with wheels were collected during the light (ZT4) and dark (ZT16) phases. Per1 and Per2 mRNA levels wer...
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Internal temporal order in the circadian system of a dual-phasing rodent, the Octodon Degus.
Chronobiology international, 2010Co-Authors: Beatriz Baño Otalora, Juan Antonio Madrid, Pablo Vivanco, Ana Maria Madariaga, Maria Angeles RolAbstract:Daily rhythms in different biochemical and hematological variables have been widely described in either diurnal or nocturnal species, but so far no studies in the rhythms of these variables have been conducted in a dual-phasing species such as the Degus. The Octodon Degus is a rodent that has the ability to switch from diurnal to nocturnal activity under laboratory conditions in response to wheel-running availability. This species may help us discover whether a complete temporal order inversion occurs parallel to the inversion that has been observed in this rodent's activity pattern. The aim of the present study is to determine the phase relationships among 26 variables, including behavioral, physiological, biochemical, and hematological variables, during the day and at night, in diurnal and nocturnal Degus chronotypes induced under controlled laboratory conditions through the availability of wheel running. A total of 39 male Degus were individually housed under a 12:12 light-dark (LD) cycle, with free wh...
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Dissociation of the circadian system of Octodon Degus by T28 and T21 light-dark cycles.
Chronobiology international, 2010Co-Authors: Pablo Vivanco, Beatriz Baño Otalora, Maria Angeles Rol, Juan Antonio MadridAbstract:Octodon Degus is a primarily diurnal rodent that presents great variation in its circadian chronotypes due to the interaction between two phase angles of entrainment, diurnal and nocturnal, and the graded masking effects of environmental light and temperature. The aim of this study was to test whether the circadian system of this diurnal rodent can be internally dissociated by imposing cycles shorter and longer than 24 h, and to determine the influence of Degus chronotypes and wheel-running availability on such dissociation. To this end, wheel-running activity and body temperature rhythms were studied in Degus subjected to symmetrical light-dark (LD) cycles of T28h and T21h. The results show that both T-cycles dissociate the Degus circadian system in two different components: one light-dependent component (LDC) that is influenced by the presence of light, and a second non–light-dependent component (NLDC) that free-runs with a period different from the external lighting cycle. The LDC was more evident in t...
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TEMPERATURE CYCLES TRIGGER NOCTURNALISM IN THE DIURNAL HOMEOTHERM Octodon Degus
Chronobiology international, 2010Co-Authors: Pablo Vivanco, Maria Angeles Rol, Juan Antonio MadridAbstract:Body temperature regulation within a physiological range is a critical factor for guaranteeing the survival of living organisms. The avoidance of high ambient temperatures is a behavioral mechanism used by homeothermic animals living in extreme environmental conditions. As the circadian system is involved in these thermoregulatory responses, precise phase shifts and even complete temporal niche inversion have been reported. Octodon Degus, a mainly diurnal rodent from Chile, has the ability to switch its phase preference for locomotor activity to coincide with the availability of a running wheel. The aims of this work are twofold: to determine whether ambient temperature cycles, with high values during the day and low values at night (HLTa), can induce nocturnal chronotypes in Degus previously characterized as diurnal; and to learn whether HLTa cycles are able to act as a zeitgeber in this dual-phase species. To this end, Degus were subjected to 24 h HLTa cycles under both 12:12 LD and DD conditions. Two e...
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Nocturnalism induced by scheduled feeding in diurnal Octodon Degus.
Chronobiology international, 2010Co-Authors: Pablo Vivanco, Antonio López-espinoza, Ana Maria Madariaga, Maria Angeles Rol, Juan Antonio MadridAbstract:Octodon Degus, a mainly diurnal rodent, characterized by its ability to shift to a nocturnal locomotor pattern under laboratory conditions, was studied to determine whether restricted food access during the scotophase could induce nocturnalism. To address this question, wheel running activity, feeding, and body temperature rhythms were analyzed for diurnal Degus housed with a wheel and subjected to either long (12 h) or short (2 h) food availability periods, in the latter case with random or scheduled food access times. The results show that allowing nocturnal feeding for 2 h, but not 12 h, can shift a previous diurnal phase preference for wheel running activity and body temperature to the scotophase, with random feeding being more effective than scheduled food availability. However, this behavioral inversion proved to be unstable, as the Degus returned to the diurnal phase within only a few days after the restricted feeding was discontinued. In addition, the negative masking effect induced by light, whic...
Luis A Ebensperger - One of the best experts on this subject based on the ideXlab platform.
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Male group members are costly to plurally breeding Octodon Degus females
Behaviour, 2019Co-Authors: Loren D. Hayes, Loreto A. Correa, Sebastián Abades, Cuilan Gao, Luis A EbenspergerAbstract:Abstract We report the results of a 6-year study of social (number of adult males/females, relatedness of females, communal litter size) and ecological (mean/CV of food abundance, soil hardness, burrow openings) factors influencing the direct fitness of plurally breeding degu (Octodon Degus) females. The best fit models for per capita offspring weaned and standardized variance in direct fitness (within-group variation) included the number of adult males per group. Per capita number of offspring weaned decreased and standardized variance in direct fitness increased with increasing number of adult males per group. Thus, females experience a cost associated with males that is not shared equally. Standardize variance in direct fitness decreased with increasing communal litter size. All other factors were not significant predictors of direct fitness variation. Our study suggests that plural breeding may not be as egalitarian as previously thought. Consequences of plural breeding may be influenced by intra- and inter-sexual conflict.
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Octodon Degus kin and social structure
Journal of Mammalogy, 2015Co-Authors: Garrett T. Davis, Enrique A. Bazán-león, Rodrigo A Vasquez, Luis A Ebensperger, Elie Poulin, Loren D. HayesAbstract:A growing body of evidence showing that individuals of some social species live in non-kin groups suggests kin selection is not required in all species for sociality to evolve. Here, we investigate 2 populations of Octodon Degus , a widespread South American rodent that has been shown to form kin and non-kin groups. We quantified genetic relatedness among individuals in 23 social groups across 2 populations as well as social network parameters (association, strength, and clustering coefficient) in order to determine if these aspects of sociality were driven by kinship. Additionally, we analyzed social network parameters relative to ecological conditions at burrow systems used by groups, to determine if ecological characteristics within each population could explain variation in sociality. We found that genetic relatedness among individuals within social groups was not significantly higher than genetic relatedness among randomly selected individuals in both populations, suggesting that non-kin structure of groups is common in Degus. In both populations, we found significant relationships between the habitat characteristics of burrow systems and the social network characteristics of individuals inhabiting those burrow systems. Our results suggest that degu sociality is non-kin based and that degu social networks are influenced by local conditions. Es creciente la evidencia que apoya la ocurrencia de especies sociales donde los individuos no estan emparentados geneticamente, lo que sugiere que la seleccion de parentesco no es indispensable para la evolucion de la sociabilidad. En este estudio se examinaron dos poblaciones de Octodon Degus , un roedor sudamericano donde los grupos sociales pueden o no incluir individuos cercanamente emparentados. Se cuantifico el parentesco genetico entre individuos en 23 grupos sociales y en redes sociales de dos poblaciones para determinar si estos aspectos de la sociabilidad dependen del grado de parentesco. Ademas, se examinaron asociaciones entre los parametros cuantificados de las redes sociales (asociacion, fuerza, coeficiente de anidamiento) y las condiciones ecologicas a nivel de los sistemas de madriguera usados por cada grupo. El grado de parentesco genetico dentro de los grupos no fue distinto del grado de parentesco entre individuos de la poblacion tomados al azar, lo que apoya que una estructura de grupos no emparentada es la regla en Octodon Degus . En ambas poblaciones se registro una asociacion entre caracteristicas ecologicas de los sistemas de madriguera y atributos de las redes sociales de los individuos que usan estas estructuras. Nuestros resultados indican que la sociabilidad en Octodon Degus no esta basada en relaciones de parentesco y que las redes sociales de estos animales dependen de las condiciones ecologicas.
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habitat type influences endocrine stress response in the degu Octodon Degus
General and Comparative Endocrinology, 2013Co-Authors: Carolyn M Bauer, Michael L Romero, Nicholas K Skaff, Andrew B Bernard, Jessica M Trevino, Jacqueline M Ho, Luis A Ebensperger, Loren D. HayesAbstract:Abstract While many studies have examined whether the stress response differs between habitats, few studies have examined this within a single population. This study tested whether habitat differences, both within-populations and between-populations, relate to differences in the endocrine stress response in wild, free-living Degus ( Octodon Degus ). Baseline cortisol (CORT), stress-induced CORT, and negative feedback efficacy were measured in male and female Degus from two sites and three habitats within one site during the mating/early gestation period. Higher quality cover and lower ectoparasite loads were associated with lower baseline CORT concentrations. In contrast, higher stress-induced CORT but stronger negative feedback efficacy were associated with areas containing higher quality forage. Stress-induced CORT and body mass were positively correlated in female but not male Degus across all habitats. Female Degus had significantly higher stress-induced CORT levels compared to males. Baseline CORT was not correlated with temperature at time of capture and only weakly correlated with rainfall. Results suggest that Degus in habitats with good cover quality, low ectoparasite loads, and increased food availability have decreased endocrine stress responses.
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Octodon Degus (Molina 1782): A Model in Comparative Biology and Biomedicine
Cold Spring Harbor protocols, 2013Co-Authors: Alvaro O. Ardiles, Francisco Bozinovic, Luis A Ebensperger, Theresa M. Lee, John Ewer, Monica L. Acosta, Alfredo Kirkwood, Agustín D. Martínez, Adrian G. PalaciosAbstract:One major goal of integrative and comparative biology is to understand and explain the interaction between the performance and behavior of animals in their natural environment. The Caviomorph, Octodon Degus, is a native rodent species from Chile, and represents a unique model to study physiological and behavioral traits, including cognitive and sensory abilities. Degus live in colonies and have a well-structured social organization, with a mostly diurnal–crepuscular circadian activity pattern. More notable is the fact that in captivity, they reproduce and live for between 5 and 7 years and exhibit hallmarks of neurodegenerative diseases (including Alzheimer's disease), diabetes, and cancer.
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The influence of trap type on evaluating population structure of the semifossorial and social rodent Octodon Degus
Acta Theriologica, 2009Co-Authors: Joseph R. Burger, Rodrigo A. Castro, Luis A Ebensperger, Adrian S. Chesh, Liliana Ortiz Tolhuysen, Ignasi Torre, Loren D. HayesAbstract:Trap type may influence captures of individuals in different age-sex categories in small mammal studies, resulting in biased population and demographic information. We deployed 4 live trap types at burrow systems of the rodent, Octodon Degus Molina, 1782, in central Chile to determine trap efficacy in capturing individuals of 6 demographic categories. We captured 2672 individuals in 17 709 trap days (15.1% trapping success). Tomahawks were the most efficient trap capturing half of individuals during both years, followed by mesh Sherman traps, large Sherman traps, and medium Sherman traps in 2005. All trap types equally sampled sexes. Large and medium Sherman traps provided similar demographic structure, where half of the individuals captured were pups; Tomahawk traps sampled more adults than pups. Relative captures of pups were similar across different trap types, suggesting that pups are equally sampled by each of the deployed trap types. Relative captures of adults were lower in Sherman traps, suggesting that this age class avoided solid-walled traps. For Octodon Degus , the sole use of Tomahawk traps may produce sufficient, unbiased demographic data. Only 4 trap mortalities occurred (0.15%). Researchers may minimize trap mortality without compromising sufficient demographic sampling by trapping during peak animal activity.
